Who's Using Your Wi-Fi? A Complete Guide to Checking Connected Devices

Have you noticed your internet has become slower and your data is running out early? Someone else might be accessing your Wi-Fi. Kaspersky, one in five routers in Russia has vulnerabilities that allow attackers to exploit someone else's network. Even if you set a password, neighbors can eavesdrop on it through weak encryption protocols or guess a simple code like 12345678.

In this article you will find 7 proven methodsHow to check who's connected to your Wi-Fi—from built-in router tools to specialized apps. We'll cover step-by-step instructions for popular models (TP-Link, ASUS, Keenetic, MikroTik), we will show you how to analyze MAC addresses and explain what to do if you detect an “outsider”. Important: Some methods require administrator rights - without them, you will only see some devices.

1. Checking via the router's web interface (universal method)

The most reliable method is to go to the router control panel. It displays all connected devices, including hidden ones (if they are active at the time of verification). The login address is usually indicated on the device's sticker (e.g., 192.168.0.1 or 192.168.1.1).

Instructions for most models:

• 🌐 Enter the router's IP address in your browser (for example, 192.168.1.1).
• 🔑 Log in (default logins: admin/admin or admin/empty password).
• 📊 Find the section DHCP Clients, Connected Devices or Local area network (the names are different).
• 🔍 View a list of devices with IP, MAC addresses, and hostnames.

Example for TP-Link:

Main Menu → Local Network → DHCP Clients

For ASUS:

Network Map → Clients

Devices with unknown names (e.g. "android-123456")

MAC addresses that don't match your gadgets

IP addresses outside your range (for example, 192.168.1.100, if you have access to 192.168.1.50)

Connections during non-working hours (at night when everyone is asleep)

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⚠️ Note: If the list contains a device with a MAC address FF:FF:FF:FF:FF:FF, this is a broadcast address - it can be ignored. But addresses like 00:1A:2B:3C:4D:5E with unfamiliar manufacturers (the first 3 pairs of characters) - a reason to be wary.

2. Using mobile apps (for quick checking)

If you're too lazy to access your router settings, use apps. They scan your network and show connected devices, but they may miss those using static IP addresses or those that are disconnected at the time of scanning.

Top 3 apps for Android And iOS:

• 📱 Fing — identifies devices by MAC, shows the manufacturer (for example, Apple, Samsung). There is a notification function for new connections.
• 🔍 WiFi Guard — compares current connections with the “white list” of your gadgets.
• 🛡️ NetScan — scans ports and identifies network vulnerabilities.

How to use Fing:

1. Install the app and connect to your network.
2. Click Scan.
3. Browse the list of devices - the application will automatically detect the type (smartphone, laptop, TV).
4. Click on an unknown device to see its MAC and manufacturer.

Fing

WiFi Guard

NetScan

Other

I don't use apps

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⚠️ Warning: Apps may display false positives if there are devices with dynamic IP addresses (such as smart bulbs or cameras) on the network. Always check MAC addresses against the router's data.

3. MAC Address Analysis: How to Determine a Device's Manufacturer

MAC address (eg. A4:83:E7:12:F5:89) is unique for each network interface. The first three pairs of characters (OUI) indicate the manufacturer. These characters can be used to determine whose device is connected. Apple, Xiaomi or an unknown brand.

How to decrypt MAC:

1. Take the first 6 characters of the address (eg. A4:83:E7).
2. Check them in the database MAC Vendors or via command:

curl "https://api.macvendors.com/A4-83-E7"

If the MAC prefix doesn't match any of your devices, you may want to block it in your router settings. For example, the address 00:1A:2B:... may belong Cisco - If you don’t have equipment from this brand, the device is definitely third-party.

4. Windows Command Prompt: Who's Online Right Now

On computers with Windows You can see active connections without third-party programs. This method will only show devices that are currently communicating with your PC.

Instructions:

1. Open Command line (Win + R → enter cmd → Enter).
2. Enter the command:

arp -a

You'll see a table with IP and MAC addresses. Compare them with your devices.

For more detailed information, use:

nbtstat -a [IP address]

For example:

nbtstat -a 192.168.1.100

This command will show the name of the device on the network (if it supports the protocol NetBIOS).

⚠️ Attention: Method arp -a This only works for devices that have recently interacted with your PC. If the "outsider" is simply connected to the router but not exchanging data, it won't be listed.

5. Checking via the terminal on macOS and Linux

Users Mac And Linux can use the terminal to scan the network. These commands provide more data than Windows, including open ports.

For macOS:

netdiscover -i en0 -r 192.168.1.0/24

(replace en0 to your network interface, and 192.168.1.0/24 - to your subnet).

For Linux (install nmap, if it is not there):

sudo nmap -sn 192.168.1.0/24

Keys:

• -sn — host scanning only (no ports).
• 192.168.1.0/24 — the IP range of your network (check in your router settings).

Example output:

Starting Nmap 7.80 ( https://nmap.org )
Nmap scan report for 192.168.1.100
Host is up (0.045s latency).
MAC Address: A4:83:E7:12:F5:89 (Apple)
Nmap scan report for 192.168.1.101
Host is up (0.032s latency).
MAC Address: 3C:5A:B4:98:76:54 (Google)

What to do if nmap is not installed?

On Ubuntu/Debian, enter:

sudo apt install nmap

On Fedora:

sudo dnf install nmap

On macOS, use Homebrew:

brew install nmap

6. Traffic Monitoring: Who's Using Your Internet

If your speed drops at a certain time, check who's consuming your traffic. The following are good options:

• 📊 Built-in router tools (section Traffic Monitor or Statistics).
• 🖥️ Programs like GlassWire (Windows/macOS) or Wireshark (advanced analysis).
• 📱 Applications NetGuard (Android) or DataMan (iOS).

Example from GlassWire:

The program shows:

• 📈 Traffic consumption chart by device.
• 🌍 Geolocation of the servers with which data is exchanged (if traffic goes to China, and you haven't been there, that's suspicious).
• ⚡ Peak loads (for example, at night when everyone is sleeping).

On routers Keenetic Traffic statistics are available here:

Internet → Statistics → Traffic by Host

7. How to block a foreign device

Found an "alien"? Here it is. 3 ways to block:

1. Through MAC filtering (most reliable):
• Go to your router settings → Wireless mode → MAC filter.
• Add your devices' MAC addresses to the whitelist.
• Activate filtering (mode Allow only specified).
2. Changing your Wi-Fi password:
• Generate a complex password (at least 12 characters, with numbers and special characters).
• Use the protocol WPA3 (if supported by the router).

Disabling DHCP for an unknown IP:

• Find the section in the router LAN → DHCP.
• Exclude the "foreigner" IP address from the pool of distributed addresses.

Example of setting up a MAC filter on TP-Link:

Wireless Mode → MAC Filtering → Enable
Add → Enter MAC (e.g. A4:83:E7:12:F5:89) → Save
Filter mode: "Allow stations from the list to access the network"

⚠️ Note: MAC addresses can be spoofed, so this method is not 100% secure. It's best to combine it with a strong password and disabling WPS (vulnerable fast connection protocol).

FAQ: Frequently asked questions about Wi-Fi testing

Is it possible to find out who is connected to my Wi-Fi if I'm not an admin?

Without administrator rights, you will only see devices that are actively exchanging data with your gadget (via arp -a or apps like Fing). The full list of connected devices is available only in the router panel.

What should I do if a device named "Unknown" appears on the network?

This could be:

• A smart device (light bulb, socket) that does not transmit a name.
• An old gadget with incorrect settings mDNS.
• A foreign device with a changed hostname.

Check the MAC address through the database MAC VendorsIf the manufacturer is unknown, block it.

How to check Wi-Fi for viruses?

Viruses can spread online through vulnerable devices (such as old routers or IP cameras). Conduct the following:

1. Network scanning Wireshark for suspicious activity (for example, packets on port 4444).
2. Checking the router for known vulnerabilities through RouterChecker.
3. Updating the router firmware to the latest version.

Can my neighbor connect to my Wi-Fi if I hide the SSID?

Hiding SSID (Skydidden Network) does not protect against connection. An attacker can:

• Guess the network name if it is standard (for example, TP-Link_1234).
• Intercept packets from your devices and find out the SSID.

Hiding your SSID only makes it more difficult for new devices to connect legitimately. It's better to use WPA3 and a complex password.

How often should I check my connected devices?

Recommended frequency:

• 🏠 Home network: once a month (or if you suspect slow internet).
• 🏢 Office/cafe: daily (via automatic alerts in Fing or router).
• 🎮 If you use P2P networks (torrents, online games): before each session.